/*
Copyright (C) 2011 by Ivan Safrin

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/


#include "PolyPhysicsScreen.h"

using namespace Polycode;

/*
void PhysicsScreen::Add(const b2ContactPoint* point) {
	if (numContactPoints == MAX_B2DCONTACTPOINTS) {
		return;
	}
	
	ContactPoint* cp = m_points + numContactPoints;
	cp->shape1 = point->shape1;
	cp->shape2 = point->shape2;
	cp->position = point->position;
	cp->normal = point->normal;
	cp->id = point->id;
	cp->state = e_contactAdded;
	
	++numContactPoints;
}

void PhysicsScreen::Persist(const b2ContactPoint* point) {
	if (numContactPoints == MAX_B2DCONTACTPOINTS) {
		return;
	}
	
	ContactPoint* cp = m_points + numContactPoints;
	cp->shape1 = point->shape1;
	cp->shape2 = point->shape2;
	cp->position = point->position;
	cp->normal = point->normal;
	cp->id = point->id;
	cp->state = e_contactPersisted;
	
	++numContactPoints;
}

void PhysicsScreen::Remove(const b2ContactPoint* point) {
	if (numContactPoints == MAX_B2DCONTACTPOINTS) {
		return;
	}
	
	ContactPoint* cp = m_points + numContactPoints;
	cp->shape1 = point->shape1;
	cp->shape2 = point->shape2;
	cp->position = point->position;
	cp->normal = point->normal;
	cp->id = point->id;
	cp->state = e_contactRemoved;
	
	++numContactPoints;
}
*/

void PhysicsScreen::BeginContact (b2Contact *contact) {
	PhysicsScreenEvent *newEvent = new PhysicsScreenEvent();
	newEvent->entity1 = getPhysicsEntityByFixture(contact->GetFixtureA());
	newEvent->entity2 = getPhysicsEntityByFixture(contact->GetFixtureB());			
	dispatchEvent(newEvent, PhysicsScreenEvent::EVENT_NEW_SHAPE_COLLISION);
}

void PhysicsScreen::EndContact (b2Contact *contact) {
	
}


PhysicsScreen::PhysicsScreen() : Screen() {
	init(10.0f, 1.0f/60.0f,10,Vector2(0.0f, 10.0f));
}

PhysicsScreen::PhysicsScreen(Number worldScale, Number freq) : Screen() {
	init(worldScale, 1.0f/freq,10,Vector2(0.0f, 10.0f));	
}

void PhysicsScreen::init(Number worldScale, Number physicsTimeStep, int physicsIterations, Vector2 physicsGravity) {
	
	this->worldScale = worldScale;
	
	numContactPoints = 0;	
	timeStep = physicsTimeStep;
	iterations = physicsIterations;
	
	b2Vec2 gravity(physicsGravity.x,physicsGravity.y);
	bool doSleep = true;
	world  = new b2World(gravity, doSleep);
	
	world->SetContactListener(this);

	updateTimer = new Timer(true, 3);
	updateTimer->addEventListener(this, Timer::EVENT_TRIGGER);
}

void PhysicsScreen::setGravity(Vector2 newGravity) {
	world->SetGravity(b2Vec2(newGravity.x, newGravity.y));
}

PhysicsScreenEntity *PhysicsScreen::getPhysicsByScreenEntity(ScreenEntity *ent) {
	for(int i=0; i<physicsChildren.size();i++) {
		if(physicsChildren[i]->getScreenEntity() == ent)
			return physicsChildren[i];
	}	
	return NULL;
}

void PhysicsScreen::destroyJoint(PhysicsJoint *joint) {
	world->DestroyJoint(joint->box2DJoint);
}


PhysicsJoint *PhysicsScreen::createRevoluteJoint(ScreenEntity *ent1, ScreenEntity *ent2, Number ax, Number ay, bool enableLimit, Number lowerLimit, Number upperLimit, bool motorEnabled, Number motorSpeed, Number maxTorque) {
	PhysicsScreenEntity *pEnt1 = getPhysicsByScreenEntity(ent1);
	PhysicsScreenEntity *pEnt2 = getPhysicsByScreenEntity(ent2);
	if(pEnt1 == NULL || pEnt2 == NULL)
		return NULL;
	
	b2Vec2 anchor((ent1->getPosition().x+ax)/worldScale, (ent1->getPosition().y+ay)/worldScale);
	b2RevoluteJointDef *jointDef = new b2RevoluteJointDef();
	jointDef->collideConnected = false;
	jointDef->lowerAngle = lowerLimit * (PI/180.0f);
	jointDef->upperAngle = upperLimit * (PI/180.0f);
	jointDef->enableLimit = enableLimit;
	jointDef->motorSpeed = motorSpeed;
	jointDef->maxMotorTorque = maxTorque;
	jointDef->enableMotor = motorEnabled;	
	jointDef->Initialize(pEnt1->body, pEnt2->body, anchor);
	
	PhysicsJoint *joint = new PhysicsJoint();
	
	joint->box2DJoint = world->CreateJoint(jointDef);
	return joint;
	
}

void PhysicsScreen::createPrismaticJoint(ScreenEntity *ent1, ScreenEntity *ent2, bool collideConnected) {

}

void PhysicsScreen::wakeUp(ScreenEntity *ent) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return;
		
	pEnt->body->SetAwake(true);
}


Vector2 PhysicsScreen::getVelocity(ScreenEntity *ent) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return Vector2(0,0);
	
	b2Vec2 vec = pEnt->body->GetLinearVelocity();
	return Vector2(vec.x, vec.y);
}

void PhysicsScreen::setSpin(ScreenEntity *ent, Number spin) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return;

	pEnt->body->SetAngularVelocity(spin);
}

void PhysicsScreen::setVelocity(ScreenEntity *ent, Number fx, Number fy) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return;
	
	pEnt->body->SetAwake(true);
	b2Vec2 f = pEnt->body->GetLinearVelocity();
	if(fx != 0)
		f.x = fx;
	if(fy != 0)
		f.y = fy;
	
	pEnt->body->SetLinearVelocity(f);
}

void PhysicsScreen::setVelocityX(ScreenEntity *ent, Number fx) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return;
	
	pEnt->body->SetAwake(true);
	b2Vec2 f = pEnt->body->GetLinearVelocity();
	f.x = fx;	
	pEnt->body->SetLinearVelocity(f);
	
}

void PhysicsScreen::setVelocityY(ScreenEntity *ent, Number fy) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return;
	
	pEnt->body->SetAwake(true);
	b2Vec2 f = pEnt->body->GetLinearVelocity();
	f.y = fy;	
	pEnt->body->SetLinearVelocity(f);	
}


PhysicsScreenEntity *PhysicsScreen::addCollisionChild(ScreenEntity *newEntity, int entType) {
	PhysicsScreenEntity *ret;
	ret = addPhysicsChild(newEntity, entType, 0,0.1,0, true);
	ret->collisionOnly = true; 
	return ret;
}

void PhysicsScreen::setTransform(ScreenEntity *ent, Vector2 pos, Number angle) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return;
	pEnt->setTransform(pos, angle);
}

void PhysicsScreen::applyForce(ScreenEntity *ent, Number fx, Number fy) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return;

	pEnt->body->SetAwake(true);
	b2Vec2 f =  b2Vec2(fx,fy);
	b2Vec2 p = pEnt->body->GetWorldPoint(b2Vec2(0.0f, 0.0f));
		
	pEnt->body->ApplyForce(f, p);
}

void PhysicsScreen::applyImpulse(ScreenEntity *ent, Number fx, Number fy) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);
	if(pEnt == NULL)
		return;
	
	pEnt->body->SetAwake(true);
	b2Vec2 f =  b2Vec2(fx,fy);
	b2Vec2 p = pEnt->body->GetWorldPoint(b2Vec2(0.0f, 0.0f));	
	pEnt->body->ApplyLinearImpulse(f, p);	
}



void PhysicsScreen::createDistanceJoint(ScreenEntity *ent1, ScreenEntity *ent2, bool collideConnected) {
	PhysicsScreenEntity *pEnt1 = getPhysicsByScreenEntity(ent1);
	PhysicsScreenEntity *pEnt2 = getPhysicsByScreenEntity(ent2);
	if(pEnt1 == NULL || pEnt2 == NULL)
		return;
	
	b2Vec2 a1(ent1->getPosition().x/worldScale, ent1->getPosition().y/worldScale);
	b2Vec2 a2(ent2->getPosition().x/worldScale, ent2->getPosition().y/worldScale);
	b2DistanceJointDef *jointDef = new b2DistanceJointDef();
	jointDef->Initialize(pEnt1->body, pEnt2->body, a1, a2);
	jointDef->collideConnected = collideConnected;
	world->CreateJoint(jointDef);
}
/*
b2MouseJoint *PhysicsScreen::createMouseJoint(ScreenEntity *ent1, Vector2 *mp) {
	
	PhysicsScreenEntity *pEnt1 = getPhysicsByScreenEntity(ent1);
	if(pEnt1 == NULL)
		return NULL;

	b2MouseJointDef *mj = new b2MouseJointDef();	
	mj->bodyA = world->GetGroundBody();
	mj->bodyB = pEnt1->body;
	
	b2Vec2 mpos(mp->x/10.0f, mp->y/10.0f);
	mj->target = mpos;
#ifdef TARGET_Number_IS_FIXED
	mj->maxForce = (pEnt1->body->GetMass() < 16.0)? (1000.0f * pEnt1->body->GetMass()) : Number(16000.0);
#else
	mj->maxForce = 1000.0f * pEnt1->body->GetMass();
#endif
	b2MouseJoint *m_mouseJoint = (b2MouseJoint*)world->CreateJoint(mj);
	pEnt1->body->SetAwake(true);
	Logger::log("OK %d!\n", m_mouseJoint);
	return m_mouseJoint;
}
*/

Vector2 PhysicsScreen::getEntityCollisionNormal(ScreenEntity *ent1, ScreenEntity *ent2) {
	PhysicsScreenEntity *pEnt1 = getPhysicsByScreenEntity(ent1);
	PhysicsScreenEntity *pEnt2 = getPhysicsByScreenEntity(ent2);	
	if(pEnt1 == NULL || pEnt2 == NULL)
		return Vector2(0,0);	
	
	PhysicsScreenEntity *rEnt1;
	PhysicsScreenEntity *rEnt2;
	for (int32 i = 0; i < numContactPoints; ++i)
	{
		ContactPoint* point = m_points + i;		
		if (point->state == 0 || point->state == 1) {	
			rEnt1= getPhysicsEntityByShape(point->shape1);
			rEnt2 = getPhysicsEntityByShape(point->shape2);						
			if((rEnt1 == pEnt1 && rEnt2 == pEnt2) || 
			   (rEnt1 == pEnt2 && rEnt2 == pEnt1)) {
				return Vector2(point->normal.x,point->normal.y);
			}
		}
	}
	return Vector2(0,0);	
}

bool PhysicsScreen::areEntitiesColliding(ScreenEntity *ent1, ScreenEntity *ent2) {
	PhysicsScreenEntity *pEnt1 = getPhysicsByScreenEntity(ent1);
	PhysicsScreenEntity *pEnt2 = getPhysicsByScreenEntity(ent2);	
	if(pEnt1 == NULL || pEnt2 == NULL)
		return false;
	
	PhysicsScreenEntity *rEnt1;
	PhysicsScreenEntity *rEnt2;
	for (int32 i = 0; i < numContactPoints; ++i)
	{
		ContactPoint* point = m_points + i;		
		if (point->state == 0 || point->state == 1) {	
			rEnt1= getPhysicsEntityByShape(point->shape1);
			rEnt2 = getPhysicsEntityByShape(point->shape2);						
			if((rEnt1 == pEnt1 && rEnt2 == pEnt2) || 
			   (rEnt1 == pEnt2 && rEnt2 == pEnt1)) {
				return true;
			}
		}
	}
	return false;
}

ScreenEntity *PhysicsScreen::getEntityAtPosition(Number x, Number y) {
	ScreenEntity *ret = NULL;
	
	b2Vec2 mousePosition;
	mousePosition.x = x/worldScale;
	mousePosition.y = y/worldScale;
	
	for(int i=0;i<physicsChildren.size();i++) {
		PhysicsScreenEntity *ent = physicsChildren[i];
		if(ent->shape->TestPoint(ent->body->GetTransform(), mousePosition))
			return ent->getScreenEntity();
	}	
	return ret;
}

bool PhysicsScreen::testEntityAtPosition(ScreenEntity *ent, Number x, Number y) {
	PhysicsScreenEntity *pEnt = getPhysicsByScreenEntity(ent);	
	
	if(pEnt == NULL)
		return false;
	
	b2Vec2 mousePosition;
	mousePosition.x = x/worldScale;
	mousePosition.y = y/worldScale;
	
	if(pEnt->shape->TestPoint(pEnt->body->GetTransform(), mousePosition))
		return true;
	else
		return false;
	
}

void PhysicsScreen::destroyMouseJoint(b2MouseJoint *mJoint) {
		world->DestroyJoint(mJoint);
		mJoint = NULL;
}

PhysicsScreenEntity *PhysicsScreen::addPhysicsChild(ScreenEntity *newEntity, int entType, Number friction, Number density, Number restitution, bool isSensor, bool fixedRotation) {
	addChild(newEntity);
	newEntity->setPositionMode(ScreenEntity::POSITION_CENTER);
	PhysicsScreenEntity *newPhysicsEntity = new PhysicsScreenEntity(newEntity, world, worldScale, entType, friction, density, restitution, isSensor,fixedRotation);
	physicsChildren.push_back(newPhysicsEntity);
	newPhysicsEntity->body->SetAwake(true);
	return newPhysicsEntity;
}

void PhysicsScreen::removePhysicsChild(PhysicsScreenEntity *entityToRemove) {
	world->DestroyBody(entityToRemove->body);
	removeChild(entityToRemove->getScreenEntity());
	for(int i=0;i<physicsChildren.size();i++) {
		if(physicsChildren[i] == entityToRemove) {
			physicsChildren.erase(physicsChildren.begin()+i);
		}
	}
}


void PhysicsScreen::Shutdown() {

}

PhysicsScreen::~PhysicsScreen() {
	delete world;
	for(int i=0; i<physicsChildren.size();i++) {
			delete physicsChildren[i];
	}
}

PhysicsScreenEntity *PhysicsScreen::getPhysicsEntityByFixture(b2Fixture *fixture) {
	for(int i=0; i < physicsChildren.size(); i++) {
		if(physicsChildren[i]->fixture == fixture)
			return physicsChildren[i];
	}
	return NULL;	
}

PhysicsScreenEntity *PhysicsScreen::getPhysicsEntityByShape(b2Shape *shape) {
	for(int i=0; i < physicsChildren.size(); i++) {
		if(physicsChildren[i]->shape == shape)
			return physicsChildren[i];
	}
	return NULL;
}
	
void PhysicsScreen::handleEvent(Event *event) {
	
	numContactPoints = 0;
	
	if(event->getDispatcher() == updateTimer) {		
		world->Step(timeStep, iterations,iterations);
	}
	/*
	for (int32 i = 0; i < numContactPoints; ++i)
	{
		ContactPoint* point = m_points + i;		
		if (point->state == 0) {	
			PhysicsScreenEvent *newEvent = new PhysicsScreenEvent();
			newEvent->entity1 = getPhysicsEntityByShape(point->shape1);
			newEvent->entity2 = getPhysicsEntityByShape(point->shape2);			
	
			dispatchEvent(newEvent, PhysicsScreenEvent::EVENT_NEW_SHAPE_COLLISION);
		} else if (point->state == 1) {
			// Persist
//			DrawPoint(point->position, 5.0f, b2Color(0.3f, 0.3f, 0.95f));
		} else {
			// Remove
//			DrawPoint(point->position, 10.0f, b2Color(0.95f, 0.3f, 0.3f));
			dispatchEvent(new PhysicsScreenEvent(), PhysicsScreenEvent::EVENT_END_SHAPE_COLLISION);			
		}
	}
	*/
	Screen::handleEvent(event);
}

void PhysicsScreen::Update() {
//	unsigned int elapsed = updateTimer->getTicks();	
//	if(updateTimer->hasElapsed()) {
//		world->Step(timeStep, iterations);
		for(int i=0; i<physicsChildren.size();i++) {
			physicsChildren[i]->Update();
		}
//	}
}